NEW YORK (Reuters) - If the U.S. healthcare legislation overhaul is not passed, or is postponed, it will put "a lot of doubt" on the "Trump trades," which include higher U.S. equities and bond yields, DoubleLine Capital Chief Executive Jeffrey Gundlach said on Wednesday.

"Surveys show that people believe the (Obamacare) repeal is the most likely part of Trump's agenda to be passed," said Gundlach, who oversees more than $101 billion in assets at DoubleLine, told Reuters. "So if you can't pass the repeal, everything else is in doubt for sure."

Investors have been bracing for Thursday's floor vote scheduled in the U.S. House of Representatives, with safe-haven securities including Treasuries and gold seeing price gains on Wednesday. Trump and Republican congressional leaders appeared on Wednesday to be losing the battle to get enough support to pass the Obamacare rollback bill.

Gundlach repeated his recommendation that investors would do better selling U.S. equities into any kind of stock rally and diversifying into emerging markets. He noted that the iShares MSCI Emerging Markets ETF has outperformed the Standard & Poor's Index by over 4 percentage points since early March.

Gundlach said Tuesday's stock-market slump illustrated how "investors are questioning whether the pro-growth U.S. policies are really going to happen."